Conventional overhead glazing systems for walkways, canopies, and the like, generally include a plurality of horizontal framing members or purlins and vertical framing members or rafters interconnected to form a structural framing unit and a top mounted pressure plate for retaining glazing panels in place against the framing unit. Typically, these conventional overhead glazing systems are assembled on-site, and the glazing panels are installed from above. Further, these conventional systems commonly utilize exterior fasteners, slots, sealing devices and holes for installing, maintaining and replacing panels.